Pz.Kpfw. I

Specifically, the mismatch in crew values caused by commander's 10% crew skill bonus. Outside of a crew of 1 commander only, 100% crew is a fiction. The client values, given for 100% crew, will normally be taken into battle with 110% crew skill members aside from specific functions, causing their actual performance to deviate from the expected client value.
These differences are taken into account in tooltip boxes.

Cons:

Performance

Armor is not bouncy to lower tier guns and most autocannons and so to make up for it some angling can be used if stuck out in the open with no other choice but absorbing damage. However it rarely works so try not to be caught in the open in this tank. The tank is best used behind cover and popping out occasionally to get shots off at a distracted enemy. The tank also has enough mobility to relocate at a reasonable rate, but give it enough time to accelerate as it lacks horsepower.

The guns are subpar for even tier 1 but with proper usage can be devastating. The Breda is advised due to the fact that most high threat tier 2 tanks have armor that is completely immune to the KwK 38's 23mm nominal pen, most notably the tank's rival, the Panzer II even from the sides. The Breda, while having a very long firing time (but better DPM), lower accuracy at range, is still better due to the extra 7mm of penetration. It is recommended to stick to close ranges and target flanks of well armored tanks, as 30mm of pen will go through anything but a H35 (the one tank to avoid at all costs unless using APCR). Basically choose the Breda for general usage, and only take the KwK if you know how to use it to its strengths (better at peek-a-booing due to rapid fire, better accuracy especially on the move, but has terrible penetration especially at this tier).

Overall, while this tank is inferior to most tier II tanks, it can really do some damage. Stick to cover, and use peek-a-boo tactics to make the most of the lowish pen and accuracy, but decent DPM. Treat this tank like a buffed tier I tank, with more speed, better armor, but the same guns as the LTraktor, minus the 37mm. With a few games you should soon be able to get to its next upgrade: the Pz 1C.